More than 60 current and former Google employees are considering bringing a class-action lawsuit alleging sexism and pay disparities against women, as the technology giant wrestles with a deepening crisis over alleged discrimination.

James Finberg, the civil rights attorney working on the possible legal action on behalf of the female employees, told the Guardian they contend they have earned less than men at Google despite equal qualifications and comparable positions.

Others, he said, have struggled in other ways to advance their careers at Google due to a "culture that is hostile to women".

The Silicon Valley company is reeling from the leak over the weekend of a male software engineer's 10-page manifesto criticizing diversity initiatives and arguing that men may occupy more leadership roles than women in tech due to "biological" differences.

Google is vehemently denying that its salaries are discriminatory. However, Finberg, who said he had interviewed about half of the 60 women who may be part of his lawsuit, said their testimony indicated there were clear disparities and prejudices that hurt women at the Mountain View company.

"They are concerned that women are channeled to levels and positions that pay less than men with similar education and experience," Finberg said. Despite similar positions and qualifications, he said, some women said they made less than male counterparts in salaries, bonuses and stock options.

Several women he interviewed have said they make about $40,000 less than male colleagues doing the same work, with one woman saying she makes two-thirds of a male peer's salary.

Of the more than 60 women who have reached out to the attorney in the last three weeks, about half still work for Google, according to Finberg, who said that more than a dozen claimed that discrimination played a role in their decision to leave the company.

One former senior manager who recently left Google told the Guardian she repeatedly learned of men at the same level as her earning tens of thousands of dollars more than her, and in one case, she said she had a male employee join her team with a higher salary despite the fact that she was his superior.

"It's demoralizing," said the worker, who requested anonymity for fear of retribution. "There's something subconsciously that happens where you do start to question the value that you're adding to the company."

The manager said that dealing with frequent sexism in the workplace and helping other women navigate the discrimination they were facing took a toll on her and contributed to her decision to quit. "After a while, it just became exhausting," she said. "It takes emotional energy that builds up over time."

Finberg argued that when men get higher compensation in the form of base salary and stocks, "the big initial disparity turns into a larger and larger disparity every year".

"I felt like I wasn't playing the game in the 'boys' club' environment," said another woman who worked for two years as a user experience designer and recently left Google. She said she regularly dealt with sexist remarks, such as comments about her looks, and that she felt it was discriminatory when she was denied a promotion despite her achievements and large workload.

"I was watching male coworkers progress at a faster rate than myself. It was really disturbing," said the designer, who also requested anonymity.

A Google spokesperson declined to comment on the pending class action. However, in reference to the women considering legal action, the spokesperson said: "Sixty people is a really small sample size." He added: "There are always going to be differences in salary based on location, role and performance, but the process is blind to gender."

While the labor department has not released details of its analysis or the scale of the pay gap it claims to have uncovered, its regional solicitor recently said that the agency's initial audit has founded six to seven standard deviations between pay rates for men and women across the company.

What that means is that there is a one in 100m chance that the observed disparity is occurring randomly or by chance, said Janice Madden, a University of Pennsylvania sociology professor who has served as an expert witness in class-action employment cases.

The former Google manager said it was upsetting to hear about the disparity. "It just makes me feel a little sick," she said. "That's a lot of missed income for me personally and the people on my team."

The Google spokesperson said the company could not comment on the standard deviations because it had not seen the labor department's analysis.

Finberg said he hoped a class-action case could have a ripple effect in the industry.

"Google is not alone in Silicon Valley," he said. "The goal of the case is to not only get Google to change its practices, but to encourage other Silicon Valley companies to change their pay practices as well."